CCB — Circular Backshell

Circular backshells for military and industrial connectors

The backshell is the component that manages the cable exit from the connector: it retains the cable, seals it and terminates the shield braid to ground. It is one of the critical points of any electrical, optical or hydraulic connection.

9 connector interfaces: MIL-DTL-38999 Series I-IV, 5015, 26482, 83723, EN2997, EN3645 and more
IP68 protection on the CB2, CB4 and CB9 series
Up to 1000 hours of salt spray resistance, depending on finish
Operating range −65 °C to +200 °C · Made in Italy · ITAR EAR FREE

Check compatibility Get the CCB catalog

Six CPE CCB series circular backshells in bright nickel-plated steel and black anodized aluminum, with laser-marked part numbers

What it is
Compatibility
CCB series
Materials and finishes
Applications
Catalog

What it is

The component that locks the cable to the connector

The circular backshell completes the interconnect, providing protection, ruggedness and mechanical continuity while eliminating weak points in the most vulnerable areas of the harness.

The backshell threads onto the rear of the connector, where tension, vibration, moisture and — on shielded cable — the break in the metal braid all converge. It carries no current: it is a mechanical and shielding component. For rectangular connectors, CPE manufactures the CRB backshell family.

Retains

Transfers cable tension to the metal body before it reaches the contacts.

Seals

Silicone O-rings, fluorosilicone on interface H; IP68 protection on the CB2, CB4 and CB9 series.

Shields

Terminates the braid to ground, keeping the electromagnetic cage closed.

Routes

Straight, 45° or 90° exit, to route the harness where space is tight.

Compatibility

The nine circular backshell interfaces

It is the first filter in any selection: if the interface doesn’t match, nothing else matters. Each key corresponds to a connector family and the specifications that govern it.

Key	Connector specifications covered
`A`	MIL-DTL-5015 MS3400 · MIL-DTL-26482 Series II · MIL-DTL-83723 Series III · EN2997 · EN3646 · LN29504 · NFC93422 HE302 · PAN6432 · PATT602
`B`	MIL-DTL-5015 solder · MS3100 · MS3101 · MS3106 — Amphenol Class A
`M`	MIL-DTL-5015 solder · MS3100 · MS3101 · MS3106 — Bendix Class A, E, R
`N`	MIL-DTL-5015 solder · MS3100 · MS3101 · MS3106 — ITT Cannon Class A, E, R
`P`	MIL-DTL-5015 solder · MS3100 · MS3101 · MS3106 — Amphenol Class R
`D`	MIL-DTL-26482 Series I solder · MS3110 · MS3116 · VG95328
`F`	MIL-DTL-38999 Series I and II · 40M38277 · NFC93422 HE308, HE309 · PAN6433-1 · PATT 614 · PATT 616
`H`	MIL-DTL-38999 Series III and IV · EN3645 · CECC 75201.002
`S`	PATT 105 · PATT 603 · PATT 608

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Send us the series, shell size and exit angle you need: we’ll confirm the correct part number, or tell you right away if it’s not in the catalog.

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CCB series

Circular Backshell — six series

For circular connectors. The six series differ on three questions: do you need shielding, do you need environmental sealing, do you need a stated IP rating? All except CB0 are available with straight, 45° and 90° exits.

CB0 series — Shrink boot adapter: CPE circular backshell variants showing shielding, environmental sealing and IP rating

CB0

Drain hole option

Shrink boot adapter

The most basic configuration: an environmental adapter designed to accept a heat-shrink boot, without shielding.

Shielded	No
Environmental	Yes
IP rating	—
Angles	Straight only

CB1 series — Environmental and shielded, lamp base thread: CPE circular backshell variants showing shielding, environmental sealing and IP rating

CB1

Standard E-nut or strain relief SR

Environmental and shielded, lamp base thread

Environmental backshell with EMI/RFI shielding and lamp base thread, available in all three exits with optional strain relief.

Shielded	Yes
Environmental	Yes
IP rating	—
Angles	Straight · 45° · 90°

CB2 series — Single band termination: CPE circular backshell variants showing shielding, environmental sealing and IP rating

CB2

Five banding options

Single band termination

Designed for single band shield termination: constant force spring band or stamped buckle band, flat or pre-coiled.

Shielded	Yes
Environmental	Yes
IP rating	IP68
Angles	Straight · 45° · 90°

CB4 series — Ring Memory Lock, IP68: CPE circular backshell variants showing shielding, environmental sealing and IP rating

CB4

Memory Ring-Lock ring

Ring Memory Lock, IP68

Environmental and shielded, with an optional Memory Ring-Lock ring for braid retention, in versions for single or double 36 AWG braid.

Shielded	Yes
Environmental	Yes
IP rating	IP68
Angles	Straight · 45° · 90°

CB8 series — With cable clamp, non-environmental: CPE circular backshell variants showing shielding, environmental sealing and IP rating

CB8

E-nut, standard or H strain relief

With cable clamp, non-environmental

Shielded, with a mechanical cable clamp, for applications where cable retention matters more than environmental sealing.

Shielded	Yes
Environmental	No
IP rating	—
Angles	Straight · 45° · 90°

CB9 series — With cable clamp, IP68: CPE circular backshell variants showing shielding, environmental sealing and IP rating

CB9

Cable clamp + IP68 sealing

With cable clamp, IP68

The most complete configuration in the circular range: shielded, environmental, with cable clamp and IP68 protection.

Shielded	Yes
Environmental	Yes
IP rating	IP68
Angles	Straight · 45° · 90°

Dimensioned drawings of the three CPE backshell exit angles: straight with rotatable coupling, 45° and 90° with miter cut — The three available exit angles — Angle S straight, Angle H 45°, Angle J 90° miter cut — in the dimensioned drawing from the CCB catalog.

Three variables beyond the series

Coupling type

Rotatable to orient the exit after tightening, direct for the most compact assembly, self-locking where vibration could loosen the coupling. CB0 is available with direct and rotatable only.

Shell size

From 08 to 61, selected to match the connector. Interfaces D and F cover sizes 08–24; interface H covers sizes 09–25 with metric threads from M12×1.0 to M34×1.0.

Shield termination

Constant force spring band or stamped buckle band on CB2, optional Memory Ring-Lock ring on CB4 (single or double 36 AWG braid), mechanical cable clamp on CB8 and CB9.

Materials and finishes

The finish determines conductivity, corrosion resistance and temperature

After the interface, it’s the choice that matters most. An anodized finish protects well but doesn’t conduct, so it doesn’t complete the shield path; cadmium conducts and resists corrosion, but it isn’t RoHS-compliant. These are trade-offs, and they should be made with the numbers in front of you.

Circular backshells — 8 combinations

Code	Material	Finish	Salt spray	Temperature	Conductive	RoHS
`B`	Marine bronze	Non-reflective shotblast	1000 h	−65…+200 °C	Yes	Yes
`C`	Aluminum	Black anodize	336 h	−65…+175 °C	No	Yes
`F`	Aluminum	Electroless nickel	48 h	−65…+200 °C	Yes	Yes
`G`	Aluminum	Black hardcoat anodize	336 h	−65…+200 °C	No	Yes
`K`	Stainless steel	Passivated	1000 h	−65…+200 °C	Yes	Yes
`J`	Aluminum	Black zinc-nickel	500 h	−65…+175 °C	Yes	Yes
`W`	Aluminum	Olive drab cadmium	1000 h	−65…+175 °C	Yes	No
`Z`	Aluminum	Black zinc-cobalt	350 h	−65…+175 °C	Yes	Yes

Source: CCB — CPE Circular Backshell catalog, ed. 04/2026, rev. 10/2026, “Material & Plating” table. Finish W (cadmium) is the only one that is not RoHS-compliant: it remains in the catalog because some military specifications still call for it.

Component materials

Component	Material
Bodies and castings	6061 aluminum, A380 alloy or 300 Series stainless steel
Shield braid	Tinned copper per QQB-575
Clamp grommets and bushings	Neoprene, silicone or fluorosilicone
O-rings	Silicone (red); fluorosilicone (blue), standard on interface H
Coupling rings and retaining rings	6061 aluminum or 300 Series stainless steel
Cable clamp hardware	300 Series stainless steel

Traceability. The catalog states that CPE uses traceable methods when sourcing and using materials, and that manufacturer certifications are kept on file and available upon request.

1000 h

salt spray, maximum

On marine bronze, passivated stainless steel and olive drab cadmium.

IP68

CB2, CB4 and CB9 series

The circular series with IP68 protection stated in the catalog.

Applications

Where these components end up

The backshell catalog does not list industries for the product line itself: it lists the CPE Group’s industries and the programs in which its products have been used. We report both, adding nothing.

Industries listed by the CPE Group

DefenseBroadcastingCommunication infrastructureMedicalTransportationNuclearOceanographic installations

CCB catalog, “Company History and new Targets” page.

Documentation

The complete catalog, in PDF

Dimensional tables, part number keys, torque values and dimensioned drawings. Leave your contact details and the download starts right away.

CCB — CPE Circular Backshell

The six circular series, the nine connector interfaces, materials and finishes, part number keys and recommended torque values. Edition 04/2026, rev. 10/2026.

Get the PDF PDF · 24 pages

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Related products. CPB heat-shrink Preformed Boots shrink directly onto compatible backshells, completing the protection of the cable exit. For rectangular connectors, CPE manufactures the CRB rectangular backshell family.

Contact

Let’s check compatibility together

With the connector part number, shell size and exit angle, we can confirm the exact part number. If what you need isn’t in the catalog, we’ll tell you right away — and assess whether it makes sense to build it to specification.

An answer from an engineer, not a switchboard
Special configurations to customer drawing
Material certifications available upon request

Check compatibility

Tell us which connector the backshell will be mounted on: we’ll reply with the correct part number or the closest alternative.